Fuel control valve



1965 K. w. HOEHN 3,199,458

FUEL CONTROL VALVE Filed June 10, 1963 2 Sheets-Sheet 1 1965 K. w. HOEHN 3,199,458

FUEL CONTROL VALVE Filed June 10, 1965 2 Sheets-Sheet 2 INVENTOR. KARL W. HOEHN ATTORNEYS United dtates Patent This invention relates to a fuel system of an engine having a fuel source, a fuel pump and a carburetor, the fuel pump being connected on one side to the source and on the other side to the carburetor. Such a fuel system is commonly found in an automobile engine, and it is in such an automobile fuel system that the present invention has found particular utility.

An engine of the type commonly found in automobiles can be thought of to operate in two states with respect to the fuel system. The first state is steady state running of the engine. In this state the fuel consumption at the carburetor is relatively low and the fuel pump is operating at a greater capacity than is required to satisfy the fuel demand. The carburetor float needle valve closes in an attempt to prevent excess fuel from entering the carburetor, with the result that the pressure of fuel in the fuel line between the fuel pump and the carburetor is relatively higher. If the float needle valve is worn or in any other way faulty, the excess pressure can result in flooding of the carburetor and overflowing of fuel from the carburetor.

The other operating state of the engine is when the engine requires excess fuel, for example during rapid acceleration. In this state the fuel consumption at the carburetor is relatively high, and as fuel is used up at the carburetor, the pressure in the fuel line between the pump and the carburetor drops. The capacity of the pump is great enough that during this operating state, the pump can deliver all the fuel to the carburetor that is required.

The present invention functions during the first operating state-that is, during steady state running of the engine (when the pressure at the carburetor is high), and cuts out during the other operating state of the engine. The invention counteracts the tendency towards flooding of the carburetor and fuel wasteage through overflowing by relieving the hi h pressure at the carburetor during steady state running.

According to the invention, a control or pressure regulating check-valve is provided in the fuel system of an engine of the type having a fuel source, a fuel pump and a carburetor. The check-valve has an inlet and an outlet, the inlet being in communication with the carburetor side of the fuel pump, and the outlet being in communication with the fuel source side of the fuel pump. Biasing means in the check-valve resiliently bias the check-valve towards its closed position. When the force exerted by the fuel at the inlet of the check-valve exceeds the force exerted by the biasing means, the check-valve opens allowing fuel to flow from the carburetor side of the fuel pump through the check-valve to the source side of the pump.

In this specification, the terms carburetor side and fuel source side of the fuel pump refer respectively to the side of the pump connected to the carburetor and the side connected to the fuel source.

It is convenient to use a ball checl -valve having a spiral spring as its biasing means. One end of the spiral spring acts against the end of a threaded stud screwed into the check-valve, and the other end of the spring acts against he ball, forcing the ball into its seat. The spring thus biases the check-valve towards its closed position.

The tension of the spring can be varied by screwing the stud in or out. The tension is set so that during steady state running of the engine, the force exerted by the fuel Edbdddb Patented Aug. Id, 1965 at the inlet of the check-valve overcomes the tension of the spring biasing the check-valve closed, with the result that the check-valve is at least partially open. Some of the fuel leaving the pump at the carburetor side is bled off and flows through the open check-valve to the fuel source side of the pump. The result is a lower pressure of fuel at the carburetor side of the fuel pump, (the pressure being a function of the tension in the biasing spring), and a constant recirculation of fuel through the pump. The rest of the fuel (i.e. the fuel that is not recirculated) flows through the fuel line to the carburetor in the conventional manner. During rapid acceleration of the engine, when more fuel is required by the carburetor, the fuel pressure at the carburetor side of the fuel pump drops as fuel is used up by the carburetor, and the fuel exerts less force on the inlet of the check-valve. Thus the checkvalve closes, stopping the bleed-off of fuel, resulting in all the fuel being pumped to the carburetor. It can be seen that the check-valve allows a lower capacity feed of fuel to the carburetor during steady state operation of the engine when this lower capacity is suiiicient, but allows the pump to deliver fuel at its maximum capacity to the carburetor during rapid acceleration.

As well as the pressure at the carburetor being normally relieved by the check-valve of the invention during steady state operation, the pressure is also less pulsating since it is substantially set by the tension in the check-valve spring. The result of this lower and less pulsating pressure is a reduction in carburetor flooding and in overflowing of fuel from the carburetor. Improved fuel economy also results because of the reduced wastage by fuel overflowing.

Another advantage of the invention results from the recirculation of fuel through the fuel pump. This causes reduced freezing and reduced vapor lock in at least the portion of the fuel system in which the recirculation takes place. This portion of the fuel system includes the fuel pump and can include part of the fuel line, depending on where the inlet and outlet of the check-valve are located.

Two specific embodiments of the invention will now be described with reference to the accompanying drawings in which:

FIGURE 1 is a side elevational in section of one embodiment of the invention,

FIGURE 2 is a plan view in section along the line II-II of FIGURE 3, showing another embodiment of the invention,

FIGURE 3 is a side elevation in section along the line IIIIII of FIGURE 2, showing the same embodiment as shown in FIGURE 2,

FIGURE 4 is a side elevation in section of a standard automotive fuel pump such as is used on American made cars, and

FIGURE 5 shows the embodiment of FIGURE 3 applied to the conventional pump of FIGURE 4.

Referring particularly to FIGURE 1, this embodiment of the invention shows a check-valve generally designated It) having a body 11 which a threaded passage 12 extending transversely through the body 11. One end of the passage I2 is connected through a coupling 113 to one end of a portion 14 of a fuel line of an engine (not shown). The other end of the line portion 14- is connected to a carburetor 16 which is connected to the en'- gine in the conventional manner and which performs its conventional function. The other end of the passage 12 is connected through a coupling 17 to one end of another portion 13 of the fuel line. The other end of the line portion 18 is connected to the carburetor side of a fuel pump 19. The fuel source side of the fuel pump 19 is connected through yet another portion 21 of the fuel line to a fuel source 22. When the check-valve Ill is installed in the fuel system as described above, the

passage 12 forms a part of the fuel line between the fuel pump 1% and the carburetor 16.

The check-valve has an inlet 23 in communication with passage 12 and hence with the carburetor side of the 'fuel pump 19. The inlet 23 opens into a chamber 24 bored axially of the check-valve body 11, and having at least its upper portion threaded as at 26.

The upper portion of the chamber 24 is blocked off by a threaded stud 27 which is screwed axially into the chamber.

The check-valve also has an outlet 28 providing another opening from the chamber 24. The outlet 23 is connected through a fuel-carrying line 29 to the portion 21 of the main fuel line between the pump and the source, so that the outlet 28 is in communication with the source side of the fuel pump.

The inlet 23 can be blocked off by a ball 31 when the ball 31 is positioned in its seat 32. The ball 31 is urged towards its seat 32 by a spiral spring 33 acting between the stud 27 and the ball 31. The spring 33 can be positioned in an axial recess 34 in the stud 27, or the spring can act against the end of the stud.

The tension in the spring 33 can be adjusted by screwing the threaded stud 27 into or out of the check-valve body 11 (i.e. towards or away from the ball 31). For this purpose the upper end of the stud 27 is provided with a slot (not shown) to allow a screw-driver to be used when adjusting the stud. A nut 36 and a washer 37 are provided on the upper end of the stud 27 which extends outside the body 11 to lock the stud in position once it has been set.

As a safety feature, in case it is desired to incapacitate the check-valve without actually removing it (in case, for example, the spring 33 should fail), the threads 26 can be extended down the chamber 24 int-o the region of the outlet 2? so that the stud 27 can be screwed down to completely block off the outlet.

In operation, the pump 19 pumps fuel from the source 22 through the fuel line to the carburetor 16 of the engine. The pump 19 operates at a pressure in excess of that required to deliver fuel to the carburetor for steady state running of the engine. This excessive pressure at the carburetor 16 is alleviated by adjusting the stud 27 so that the tension in the spring 33 acts on the ball 31 With less force than does the fuel in the passage 12, and the ball 31 is moved out of its seat 32, thus opening the check-valve 10. Some of the fuel in the passage 12, instead of continuing through the line 14 to the carburetor 16, flows through the inlet 23 into the chamber 24, out the outlet 28 and through the line 29 to the line 21 from where it flows back into the fuel pump 19 at the source side. That is, some of the fuel is bled off from the carburetor side of the fuel pump through the 'check valve 1t and returned to the source side of the fuel pump.

The affect of this bleed-off of fuel when the engine is running in a steady state is a reduced pressure at the carburetor, to counteract flooding of the carburetor and fuel spillage. This is especially valuable if the float needle valve of the carburetor is worn, since under this condition flooding and spilling are more pronounced. The check-valve also reduces the pulsating effect usually associated with fuel pumps by maintaining the pressure fairly steady at the carburetor. The pressure is controlled by the tension in the spring 33. Furthermore, the constant recirculation of fuel through the fuel pump and part of the fuel line counteracts freezing and vapor lock.

Whenever excess fuel is required by the carburetor 16, such as during rapid acceleration of the engine, the fuel pressure at the inlet 23 drops as more fuel is used up by the carburetor. When the pressure drops so low that it can no longer overcome the force applied by the spring 33 on the ball 31, the spring moves the ball 31 back into its seat 32, closing the check-Valve and stopping the bleed-off of fuel. Under these circumstances, all the fuel being pumped by the pump 1? flows through the normal fuel line to the carburetor 16. Thus, when the carburetor 16 needs the excess fuel which the pump 19 is pumping, the check-valve cuts out preventing the excess fuel from recirculating and allowing all the fuel to be supplied to the carburetor.

Another embodiment of the invention is illustrated in FIGURES 2 and 3. This embodiment is adapted to be incorporated into a conventional fuel pump of an engine. In FIGURE 3, part of the fuel pump is shown to more clearly demonstrate the interaction between the pump and the check-valve of the invention. In the embodiment shown, the check valve replaces a separator normally present between the header bowl of the pump and the pumping chambers. The check-valve and the conventional separator have some features in common. Each has a passage 49 through which fuel flows from the source (not shown) to enter a chamber 41 in open communication with the header bowl 42. A channel 43 through the check-valve connects the header 42 with an inner or inflow chamber 44 in the fuel pump at the source side. The fuel flows from the header 42 through the channel 43 to the inner chamber 44- from where it is pumped to an outer outflow chamber 46 in the fuel pump at the carburetor side. In a conventional fuel pump not employing the invention, the fuel would then flow from the other chamber 46 through a line directly to the carburetor.

In the embodiment of the invention drawn in FIGURES 2 and 3, the check-valve has an inlet 47 in communication with the outer chamber 46, and an outlet 48 in communication with the header bowl 42. As was the case in the embodiment of FIGURE 1, a ball 49 is biased towards its seat 51 by a spiral spring 52. When the ball 49 is in position in its seat 51, the passage between the inlet 47 and the outlet 48 is blocked off. Also as in the previous embodiment, a threaded stud 53 controls the tension of the spring 52, and the stud 53 has a nut 54 and a washer 5b to lock the stud in a preset position.

The operation of this embodiment of the invention is the same as the operation of the embodiment of FIGURE 1. When the pressure of fuel in the outer chamber 46 acts on the ball 2-9 with greater force than does the spring 52, the ball moves out of its seat and allows fuel to flow from the outer chamber 45 back into the header 42 from where it is recirculated through the pump. When the pressure in the outer chamber drops low enough, the spring 52 returns the ball 49 to its seat 51, preventing the bleed-off of fuel.

FIGURE 4 is a section view of a typical known fuel pump for a standard American automobile having a bowl structure 42, a separator member S therebeneath and inlet and outlet non-return valves 61 and 62 respectively controlling inward flow to the inflow chamber 54 and outward flow to the outflow chamber 46. These chambers 44 and 46 being also indicated in phantom in FIGURE 3.

It will be seen that the rocker actuating arm 65 is received within a clearance slot 66 in the diaphragm spindle 67 thereby permitting lost motion between the actuating mechanism and the diaphragm structure 68 to provide automatic stroke compensation as is well known in the art.

The diaphragm structure 68 includes upper and lower diaphragm plates 69 and 70 together with a diaphragm return spring 71.

The header bowl 42 in FIG. 4 communicates with the pump inflow chamber 44 by way of channel 43. The fuel enters the pump 53 by way of entry passage 5% in the separator S flowing upwardly into the bowl 42 and downwardly through the separator by channel 43.

The pump separator S for which the check-valve 11 of the present invention is substituted is secured to the. lower body of the pump by means of a screw (not shown). in the bottom of chamber 4-1. When the check-valve 113 is substituted, it is similarly secured to the lower body of the pump.

In the embodiment of FIG. 5, the check-valve of the present invention is shown installed in position on the pump 58. Like parts are similarly numbered.

The present invention has been applied to all types of conventional automotive fuel pumps as used on American cars with or without header bowls.

What I claim as my invention is:

1. An automotive fuel pumping combination of the diaphragm type adapted to vary the pumping stroke with varying fuel back pressure to regulate the fuel output pressure comprising a first housing; diaphragm pumping means carried by said first housing; a second housing comprising an inflow chamber, an outflow chamber and valve means in each of said chambers for establishing fluid flow communication with the diaphragm pumping means; a removable cover housing for said second housing; a further separator housing interposed between and coupled to both the second housing and the removable cover housing; said further housing including inlet and outlet pasages therethrough to establish fluid communication with the inflow chamber and the outflow chamber respectively of said second housing; a pressure regulating check-valve in said outlet passage normally closing said outlet passage up to a predetermined fuel output pressure; said outlet passage comprising a bypass around the fuel pumping combination; said fuel pumping combination including fuel ingress and egress ports to said chambers; said further housing being adapted to convert pumps not having a bypass capability to pumps with such a capability by virtue of the addition of said further housing.

2. The pump combination of claim 1 wherein said outlet passage in said further housing comprises at least a pair of intersecting passageways in fluid communication, one of which is adapted to be closed by said check valve, and wherein said check valve comprises movable closing means and biasing means for biasing said movable closing means normally to close completely said one of the passageways.

3. An automobile fuel pump combination having automatic pressure limitation by pump stroke regulation, comprising a pump housing including a chamber; a deformable diaphragm sealingly extending in fuel inductive and pumping relation across said chamber; movable spindle means connected with said diaphragm to produce deformation thereof in a first direction; a diaphragm return spring to move said diaphragm oppositely of said first direction; pump driving means mechanically connected with said movable spindle and including a lost motion connection to permit automatic working stroke adjustment of the diaphragm when in operation, as a function of diaphragm return spring force and pump output fuel pressure; non-return inflow and outflow valves within the pump housing sealingly defining said chamber; said fuel pump combination housing including an inflow chamber and an outflow chamber, respectively in fluid communication With the non-return inflow and outflow valves defining the ingress and egress sides respectively of the pump; a separate adaptor housing connected to the pump housing; said adaptor housing including a bypass passage having its inlet in fluid communication with the fluid egress side of the pump and its outlet in fluid communication with the fluid ingress side of the pump when connected to the pump housing; a pressure responsive bypass check-valve in the adaptor housing to control fluid flow from the egress side of the pump to the ingress side of the pump in response to fluid pressure above a predetermined value, said pressure responsive bypass check-valve being set to bypass fluid at a pressure less than the maximum output pressure which would be generated by the automatic stroke regulator means of a pump not having the bypass capability whereby the pump egress pressure is limited by the setting of said check-valve.

References Cited by the Examiner UNITED STATES PATENTS 1,153,401 9/15 Milne 137-539 X 1,305,964 6/19 Dickson 137-539 X 1,780,217 11/30 Wiltse 137-539 X 1,912,842 6/33 Hobbs.

1,913,128 6/33 Peter 103-42 2,056,259 10/36 Cummins 158-364 2,104,448 l/33 Babitch 123-1395 2,527,352 10/50 Christian 158-363 X 2,739,538 3/56 Witchger 103-42 X 2,901,031 8/59 Powell et a1. 158-364 FOREIGN PATENTS 804,767 11/5 8 Great Britain.

FREDERICK L. MATTESON, 111., Primary Examiner.

MARTIN P. SCHWADRON, JAMES W. WESTHAVER,

Examiners. 

1. AN AUTOMOTIVE FUEL PUMPING COMBINATION OF THE DIAPHRAGM TYPE BACK TO VARY THE PUMPING STROKE WITH VARYING FUEL BACK PRESSURE TO REGULATE THE FUEL OUTPUT PRESSURE COMPRISING A FIRST HOUSING; DIAPHRAGM PUMPING MEANS CARRIED BY SAID FIRST HOUSING; A SECOND HOUSING COMPRISING AN INFLOW CHAMBER, AN OUTFLOW CHAMBER AND VALVE MEANS IN EACH OF SAID CHAMBERS FOR ESTABLISHING FLUID FLOW COMMUNICATION WITH THE DIAGRAM PUMPING MEANS; A REMOVABLE COVER HOUSING FOR SAID SECOND HOUSING; A FURTHER SEPARATOR HOUSING INTERPOSED BETWEEN AND COUPLED TO BOTH THE SECOND HOUSING AND THE REMOVABLE COVER HOUSING; SAID FURTHER HOUSING INCLUDING INLET AND OUTLET PASSAGES THERETHROUGH TO ESTABLISH FLUID COMMUNICATION WITH THE INFLOW CHAMBER AND THE OUTFLOW CHAMBER RESPECTIVELY OF SAID SECOND HOUSING; A PRESSURE REGULATING CHECK-VALVE IN SAID OUTLET PASSAGE NORMALLY CLOSING SAID OUTLET PASSAGE UP TO A PREDETERMINED FUEL OUTPUT PRESSURE; SAID OUTLET PASSAGE COMPRISING A BYPASS AROUND THE FUEL PUMPING COMBINATION; SAID FUEL PUMPING COMBINATION INCLUDING FUEL INGRESS AND EGRESS PORTS TO SAID CHAMBERS; SAID FURTHER HOUSING BEING ADAPTED TO CONVERT PUMPS NOT HAVING A BYPASS CAPABILITY TO PUMP WITH SUCH A CAPABILITY BY VIRTUE OF THE ADDITION OF SAID FURTHER HOUSING. 